Washington (CNN) - Newt Gingrich is amplifying his call for Secretary of State John Kerry to resign over his comments that climate change represents the biggest challenge “of our generation.”

"I think it's very troubling that our secretary of state … believes that climate change is a greater danger than a nuclear war," Gingrich said Tuesday in an interview with CNN’s Wolf Blitzer on “The Situation Room.”

The CNN Crossfire co-host and former House speaker took to Twitter on Monday night, writing that "Every American who cares about national security must.demand Kerrey's (sic) resignation.A delusional secretary of state is dangerous to our safety."

Every American who cares about national security must.demand Kerrey's resignation.A delusional secretary of state is dangerous to our safety

Gingrich said he was “quite prepared to defend the argument that nuclear war is a far bigger threat to our society than is climate change.”

On Sunday, Kerry delivered one of the strongest speeches on climate change by any American official while visiting Indonesia, which has lost more than 40% of its tropical forests that store carbon absorbed from the atmosphere.

Kerry said "climate change can now be considered another weapon of mass destruction, perhaps the world's most fearsome weapon of mass destruction." He also called it "the greatest challenge of our generation."

Gingrich added in his CNN interview that Kerry was not a senator just giving “some wild speech to please the left,” noting that the top U.S. diplomat should be held to a "higher level of seriousness."

CNN has reached out to the State Department for reaction to Gingrich's comments.